[lephoenix]

Can we run e85 in our cars? I tried searching but 3 characters is too short for the search feature.
I've seen other cars make double digit gains from the higher octane from e85. I don't know if I would expect that but we may get some results.

 

[warpig]

NO it will tear up the GDI pump and the seals

 

[lephoenix]

Ah. Ok. That's what I kind of assumed.
With the talk about octane levels I thought I might as well ask.

 

[Scoobdude]

Not questioning you warpig, but gotta link to that?

 

[Crosive]

http://forums.turbobricks.com/showthread.php?t=73061

Good read on the subject

Sent from my SM-N900P using Tapatalk

 

[Scoobdude]

Just to add to this I have several thousand miles with e85 and other mixtures ratios with no problems to report. Wrx has160k miles on it so with stock injectors. Pump was replaced with high flow pump due to manufacturer of high flow pump wanting to know if ethanol did have any negative effects.

So when somewhere says something will fail i would like to know. GDi is a different beast and I still have room to learn. So please if you have a link to failed parts please let us know.

 

[Playwithmymind]

That article explains basically why we shouldn't use e85 or e100 in our cars. First is the ecu is not setup for the different afr needed for e85 and the fuel system might fail in wide open throttle or under heavy acceleration since it was not designed for running that volume of fuel. We are not Flex Fuel compatible.
With some work LPFP, HPFP, larger fuel lines, and injectors along with a custom ecu tune you might be able to make it work but then you are stuck running e85 and unable to use reg 93. If you travel you would most likely be screwed since places like where I'm at don't even have e85 available.
It is very similar to the setup needed for running alcohol

 

[Scoobdude]

Understood. In Stock form it is not possible to run full e85 due to limitations in fuel trims. But for now, until some sort of live tuning is available, i am look for post failures. Most cars after the obdII regulations are made not to be bothered by the slight increase of corrosivness of ethanol. We can already run e10 without issue.

That being said, a mixture that stays within your fuel trims, and still keeps your idc well below 100 should work fine imho.

On my subaru, we tricked the ecu into thinking it had different sized injectors. This change could be made real time. And because the O2 sensor looks for lambda, not afr your system ran fine. Lambda is the same across ethanol, methanol, and gas. But 1 lambda is not the same afr across those fuels.

With all that being said, a 30% mixture is what I still run on my subaru now. It didn't affect mpg (which was bad due to the new gearing) but added some low end touque and lowered egts a bit. And I am hoping the same can be done for the optima and forte turbos.

 

[Playwithmymind]

With all the data logging I have done I have never had the IDC over 28% so we might be safe with a 30% mix on stock fuel system. It may allow the ECU to add a little extra timing. When I stated changing out the parts for the fuel system it wasn't about the corrosive properties of E85 it was the 30-40% increase in volume needed to run straight ethanol that our stock setup might not handle.
I should have been a little more informative when I mentioned the AFR. Remapping the ECU for the changes needed to properly get the efficiency from E85 and not flood the cylinder. At idle there would be very little to no difference between the two fuels but under WOT or heavy throttle is where the problem would occur. Considering at WOT on 93 I am dropping AFRs down to low 10s and high 9s I would guess the ECU mapping is set for a ratio around that or close to it in those conditions. To my knowledge using ethanol with that mapping for gasoline would basically flood the cylinder and have a negative effect on performance. We run a 15/10/75 mix of 116 (15), Nitro (10) and methanol (75) in the race car and have a very little change in the goal AFR from idle to [email protected] lb of boost. At Idle we are at 7.9 and WOT down the track it is 6.4, we could lean it out a little more but better safe than boom (this is using a afr gauge for methanol).
We do have it available randomly throughout the state and I might consider a mix increasing it 5% every other fill up to see what differences it makes. Then try to talk Tork into making changes in the tune to accommodate the mix (more timing and lean it out some).

 

[Playwithmymind]

With all that being said, a 30% mixture is what I still run on my subaru now.

This 30% mix, are you accounting for the 10% in E10/reg 93 or is it an additional 30%?

 

[warpig]

Not questioning you warpig, but gotta link to that?

no links but we talked about it in class, I tried to look for it in KGS but could not find anything. If I get time i'll try to search Kia stuff better might be in owner manual too

 

[Scoobdude]

Awesome warpig. Let me know if you find anything.

Mind, yes. I have a spreadsheet i would use on gdrive and it would also keep track of octane. And you would plug in tge previous tanks volume and it would add it in to the mix as well. Kinda like this

(tank size) - e85 gallons - gas gallons = gallons in tank.

Insert previos octane + octane of gas + octane of e85 = divide by the ratio of total gallons.

Any way just remember that the 02 sensor is looking for lambda. So change your mindset to the 1lambda = stoich and you will see that 0.75 lambda is 75% of tgr stoich value of the fuel you are running. Afr is a calculation off of lambda basically.

28% idc is the most you have seen targeting those afrs with a tune?

The idc is only for injector head room. Fuel trims are for the change in lambda due to a new stoich target. Like atmospheric changes and weather changes. this is what prevents us from running full e85 out the box. My wrx can only adjust for a 25% change which is fine for 30% ethanol on that set up. But if you put enough to trip the cel then that is when the ecu cannot compensate any further. You will run lean from idle to wot.

Hope that helps. I will see if I can find the spreadsheet if you guys want it?

 

[Scoobdude]

Found this one. Not mine but it has some interesting things mine didn't. Will see if I can get around to adding the previous tank specs into this one like I had on mine. Enjoy



https://www.ecmtuning.com/wiki/e85fuel

P.s our tanks are 13.2 gallons. So each unit on our gauge is roughly 1.1 gallons (us)

 

[Playwithmymind]

Any way just remember that the 02 sensor is looking for lambda.

Well I would hope most on here know the O2 sensor does not look for lambda, it simply measures the amount of oxygen in the exhaust which is read by the ecu and put into the calculation along with other readings and predetermined factors to calculate the current point so the ecu can make adjustments to achieve the predetermined point in what most refer to as a map (no not manifold absolute pressure). Some software used to modify fuel curves will use AFRs as a reference and calculate it to the needed format behind the scenes.

For 95% of the readers that know what AFRs are and what it refers to I prefer to keep it understandable to a point and for the maybe 20% that have heard of Lambda and know what stoich values are I would hope they can still comprehend what AFRs are. Built a lot of car and trucks and to this day have yet installed a Lambda gauge lol. There is no need to change my mindset when this is not a tuning forum or a tuning thread for that matter.

 

[6thElementEngineering]

1 Lambda = 14.7:1 stoichiometric air/fuel ratio

I don't know the language regarding this that's programmed in the ECU. That's the relation though.

 

[Playwithmymind]

and stoich for pump gas in a perfect non E10 fuel is 14.7 but seeing all we get is E10 actual stoich is around 14.216 (changes by station, age and exact amount of ethonal (not always 10%)). So it would look like this in calculation, I am at 10.6 AFR at 5800 rpm so (10.6/14.7)*14.216=10.251 10.251/14.216=.72 therefore Lambda =.72 it's not hard to calculate but you still have to know AFRs to get to lambda or while modifying a tune you still need to have more info than just lambda to get the AFRs where you want them. Correct?

 

[Playwithmymind]

Now to throw E85 in the mix that has a stoich value of 9.86 and at 5800 rpms you are at 7.6 AFR it would be (7.6/14.7)*9.86=5.098 5.098/9.86=.52 Lambda =.52 So the actually mapping on a E85 tune may have a lean Lambda number of .65 and a rich side of .52 then?

 

[Scoobdude]

Lambda is what your ecu and 02 reads. lambda has a direct correlation to stoich which changes based on fuel.

So 1 lambda would be 14.7 on gas and 9.76 on e85.

But a bit deeper in the map you would see a 12:1 ratio which would be a conversion to gas. But you are running e85. So you must convert it to lambda first. (12 / 14.7=0.81....) Which would be 0.81 lambda. Now you would need to convert that to e85 to get your actual afr. (9.76 * 0.81= 7.90:1).

So basically afr is a calculation off of lambda based on fuel type. The ecu does not target afrs, it targets lambda. 14.67 in e10 would run you lean as stoich is for e10 is 14.06.

Hope that helps.

 

[Playwithmymind]

So 1 lambda would be 14.7 on gas and 9.76 on e85.
But a bit deeper in the map you would see a 12:1 ratio which would be a conversion to gas. But you are running e85. So you must convert it to lambda first. (12 / 14.7=0.81....) Which would be 0.81 lambda. Now you would need to convert that to e85 to get your actual afr. (9.76 * 0.81= 7.90:1).
14.67 in e10 would run you lean as stoich is for e10 is 14.06.
Hope that helps.

Yes that makes sense thanks. Never played with E85 (yet).
After not doing anything for sometime (almost 2 yrs) just checked the date release on the software I was using, yup it's old 2004. It is amazing how much has changed and how much has been forgotten. Scoobdude keep the information flowing this is turning into a refresher course lol.

I use stoich 14.216 for the E10 I get at the same station which is always between 8.6-8.9% ethanol and 14.13 for most other places since no 2 stations are the same. The 12:1 ratio would be more along the lines of an NA engine correct? and we would use 11.3:1 ratio for FI engines if I'm not mistaken which would put it right around 10.95:1 AFR (this would be for WOT?). Just waiting on someone to release software to tune these 1.6Ts through the OBDII port that isn't $3500 so I can relearn what has been forgotten and changed.

 

[Scoobdude]

The 12:1 was just an example. Tork or someone who tunes these would know better than I on what is to rich etc for this motor. For subaru i think 11s is about where you want to be. These might be different as I am new to direct injection + inline kia motors.

But yes would be awesome if we could get some running software. At least enough to switch between a e85 map and a gas map.

And it's a refresher for me too. Been having to reread my posts and correct stuff cause I am old